Dixon Waltham Chalk, 3.25 x 0.4375" Sticks, Tapered, 144 Pieces per Box, White (33144) Works well on concrete, stone, asphalt, metal and paperboard Traditional white chalk is safe for classrooms Box of 144 pieces Conforms to ASTM D-4236 safety standards Earn free supplies - Visit the Prang Power website for program information